TommyD wrote:Bill, although I think what you posted is a good visual of the Agile process, I think when people talk about the agile triangle they are usually referring to something like this, below, I think.

That's why I started by saying I am no expert However, I'm glad you though that what I posted was also useful

Thanks. I see the three areas that are being addressed by the triangle's points and it makes sense, but how/why is it always being used to demonstrate the differences between Waterfall and Agile? That's the part I'm having a hard time figuring out.

I have not failed. I’ve just found 10,000 ways that won’t work - Thomas A. Edison

There are many versions of the "triangle" that people use. Traditional plan-driven projects are based on the triangle of Time, Cost and Quality. All requirements have to be accounted for in the requirement phase and then the project is planned around the expected features to be delivered when the project is completed. The features are the first ones to be fixed, afterwards an estimation of time and costs for delivering those features is obtained. In the Agile framework, on the other hand, the goal is to fix time and cost and manage a variable scope. This in turn results in the ability to meet deadlines both in the short and long term. Approaching a project this way makes easier to focus on features that add business value and to avoid building features that may never, or rarely be used. Like Vilfredo Pareto, an Italian economist, observed in 1906, 80% of the land in Italy was owned by 20% of the population. He also observed that 20% of the pea pods in his garden contained 80% of the all peas. So he came to formulate his principle, "Pareto's Principle", observable in business, i.e., that “80% of your sales come from 20% of your clients”. By extension, 80% of the customers use only 20% of the features of a product. Consistent with that, it would be great if you could avoid building features that will never be used and instead concentrate on those that will be used and therefore add value to your project.

The traditional triangle of Time, Cost and Quality is inverted in the Agile framework to visually denote the process of fixing the cost and managing the scope.